Apparatus for cutting and shredding wood

ABSTRACT

An apparatus for cutting and shredding wooden materials such as tree limbs and the like includes an inclined chute for receiving the material and delivering the same to a cutting station, a cutting bar mounted at the end of the chute adjacent such cutting station, and a cutting drum in operative juxtaposition to the cutting bar. Manganese steel teeth made by cutting a bar of square cross section on parallel planes forming an acute angle with the longitudinal axis of the bar are welded to the periphery of the drum in a spiral wrap. A feed roll is pivotally mounted at the sides of the chute such that it can float on the materials on the floor thereof to urge the same into contact with the drum.

[ Apr. 2, 1974 APPARATUS FOR CUTTING AND SHREDDING WOOD [76] Inventor:Wayne H. Kubitz, Rt. 1 Box 840,

Sandy, Oreg. 97055 [22] Filed: Mar. 1, 1972 [21] Appl. No.: 230,885

[52] US. Cl 241/225, 144/l72,241/294 [51] Int. Cl. 1302c 4/20 [58] Fieldof Search 241/221, 224, 225, 189 R,

FOREIGN PATENTS OR APPLICATIONS Germany 241/293 PrimaryExaminer-Granville Y. Custer, .lr. Assistant Examiner-Howard N. GoldbergAttorney, Agent, or Firml(larquist, Campbell, Leigh, Hall and WinstonSparkman,

[57] ABSTRACT An apparatus for cutting and shredding wooden materialssuch as tree limbs and the like includes an inclined chute for receivingthe material and delivering the same to a cutting station, a cutting barmounted at the end of the chute adjacent such cutting station, and acutting drum in operative juxtaposition to the cutting bar. Manganesesteel teeth made by cutting a bar of square cross section on parallelplanes forming an acute angle with the longitudinal axis of the bar arewelded to the periphery of the drum in a spiral wrap. A feed roll ispivotally mounted at the sides of the chute such that it can float onthe materials on the floor thereof to urge the same into contact withthe drum.

8 Claims, 10 Drawing Figures PATENTH] APR 2 I974 sumiur a PATENYED APR 2I974 SHEET3UF3 APPARATUS FOR CUTTING AND SHREDDING WOOD BACKGROUND OFTHE INVENTION This invention relates to apparatus for cutting wood and,more particularly, to apparatus particularly adapted to crushing,shredding and cutting the wood into pieces which exhibit rapid decaycharacteristics.

A wide variety of apparatus has heretofore been available for cuttingwooden materials into chips or pulverizing the same into sawdust. Theend products of such apparatus, however, do not decay very quickly. Infact, when spread on the ground, they tend to remain relatively inertand compact and resist biological breakdown.

Such prior apparatus also has been particularly vulnerable to rock andmetal which often is embedded in the wood. Nails, rocks and railroadspikes often damage the teeth or cause them to break.

Accordingly, it is the primary object of the present invention toprovide an apparatus that will crush, shred and cut wooden materialsinto pieces that exhibit superior biological breakdown or decaycharacteristics.

A further object of the present invention is to provide such anapparatus that will be relatively immune to damage from rocks ormetallic pieces embedded in or included with the wooden materials.

A further object of the present invention is to provide such anapparatus that will be relatively inexpensive to construct and maintain.

SUMMARY OF THE INVENTION My apparatus includes chute means for receivingwooden materials and delivering the same to a cutting station. A cuttingbar is mounted on one end of the chute means and has a cutting edge onwhich the material is cut. A cutting drum is positioned adjacent suchend of the chute means, the drum being mounted for rotation about anaxis transverse to the longitudinal axis of the chute means.

A plurality of hard metal teeth are attached to the periphery of thedrum in a spiral wrap. The teeth comprise segmets of a rectangular barcut on parallel planes, such planes forming an acute angle with thelongitudinal axis of the bar. Preferably the teeth comprise manganesesteel teeth.

Means are provided to move the wooden material along the floor of thechute to the cutting station, and power means are provided for rotatingthe drum to cut the same.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of anapparatus constructed in accordance with the present invention, portionsthereof being shown detached for clarity of illustration.

FIG. 2 is a longitudinal sectional view through the apparatus of FIG. 1.

FIG. 3 is a top view of the apparatus.

FIG. 4 is a partial end view of the cutting drum illustrating the mannerof attachment of the cutting teeth thereto.

FIG. 5 is a developed view of the surface of the drum illustrating thedisposition of the teeth thereon.

FIG. 6 is a vew illustrating the teeth and the manner in which they arecut from a rectangular bar.

FIG. 7 is a top view of an alternate form of tooth suitable for use withthe present invention.

F IG. 7A is a side view of the tooth illustrated in FIG 7.

FIG. 8 is a top view of another form of tooth suitable for use with thepresent invention.

FIG. 8A is a side view of the tooth of FIG. 8.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings,the apparatus includes a frame 10 having legs 11 and supporting aninclined metal feed chute 12 having a floor 13 and sides 14 supported onangle members l5, 16 at a desired forward pitch. Each of the sides 14has an arcuate slot 17 cut therein for a purpose hereinafter to bedescribed.

A feed roll 20 adapted to rotate on a horizontal axis 19 is pivotallysupported by a structure 21 including vertical angle members 22 and ahorizontal top plate 23. The members 22 are welded to the forward end 24of the frame at each side thereof. Members 22 are joined by horizontalangle members 25 to form an overhead support.

A cutting drum 26 having a horizontal axis 27 transverse to thelongitudinal axis 28 of the chute 12 is mounted for rotation in bearings30 supported on the frame 10 between the vertical members 22 on eachside thereof. Power for the drum 26 is provided through a drive shaft 29from any desired source as, for example, the power takeoff of a farmtractor.

A cutting bar 31 preferably made from 11 to 14 percent manganese steelis bolted to the angle member 16 at the forward end of the chute 12 toform a bed knife on which the wooden materials are cut. A dischargechute 32 comprising an upwardly curved receiving plate 33 welded to theangle member 16 at its upstream or receiving end and supported by thelegs 11 at its discharge end is positioned below the drum 26 to receivethe cut materials and discharge the same from the forward end 24 of theapparatus.

A feature of the invention resides in the geometry of the location ofthe cutting drum 26 with respect to the floor 13 of the chute l2 and thecutting bar 31. Referring to FIG. 2, a radial plane 35 drawn through theaxis 27 of drum 26 and including the cutting edge 36 of the bar 31 isseen to form an acute angle A with the floor 13 of the chute l2. Angle Ais small enough that wooden materials such as tree limbs and the likeare not drawn under the drum 26 so as to jam the same. The periphery ofthe drum 26 is seen to dependbelow the plane of the floor 13. Were angleA of a larger magnitude such that the position of the cutting bar 31were further to the left as viewed in FIG. 2 and perforce positionedbelow the present level, wooden materials might be drawn through thedischarge chute 32 without being crushed or cut, thereby to jam thedrum. If this were the case, the cut pieces might also be too long orstringy.

The angle A is also sufficiently large to facilitate the self feeding ofthe wooden materials into the space defined by the periphery of the drum26 and the edge 36 of the cutting bar 31. Stated otherwise, were theangle A of a smaller magnitude such that the position of the cutting bar31 were upwardly and further to the right as viewed in FIG. 2, woodenmaterials would tend to impinge upon the periphery of the drum 26 andmight ring are facilitated.

A preferred magnitude for angle A has been found to be about 45. At thisvalue, jamming of materials in the discharge chute 32 is eliminated, yetflow of materials through the space defined by the periphery of the drum26 and the edge 36 of the cutting bar 31 is facilitated. The result isthat the drum 26 is positipned forwardly of the cutting bar 31 with itsperiplfery depending below the floor 13 of the chute.

The feed roll 20 is journaled between arms 40 pivotally mounted forrotation on bolts 41 received in brackets 42 attached to the rearwardvertical angle member 22. The arms 40 are joined by a verticalstiffening frame 43. The roll 20 is powered for rotation in the samedirection as the drum 26 through a chain and sprocket drive 44 by ahydraulic motor 45 mounted on a bracket 46 on one arm 40. Motor 45 issupplied by hydraulic fluid through a control valve 47 supported on theangle members 25. The hydraulic fluid may, for example, be supplied bythe hydraulic system of the farm tractor. The control valve 47 isadapted to provide both torque and'speed controls for the motor 45 suchthat the roll 20 has a wide range of possible speeds. In this mannerlight materials are fed to the drum 26 with the roll 20 operating athigh speed; bigger and heavier materials are fed with the roll operatingt slow speeds.

It should be understood that the roll 20 need not be drivenhydraulically in the manner described. It could also be driven by thesame means as the drum 26 through suitable speed reducing means.Furthermore, the feeding means to supply the wooden materials to thedrum 26 need not comprise the feed roll 20 shown. Such could, forexample, take the form of a belt eonveyor positioned in a manner to movematerial along the chute to the cutting station. Other moving meansmight suitably be employed.

A plurality of transversely extending feeder plates 48 are attached tothe periphery of the feed roll 20 as shown. The plates 48 are notpositioned radially, but are biased in the direction of rotation of theroll so as to facilitate the feeding of materials to the drum 26.Pivotally supporting the arms 40 on the brackets 42 permits the entirefeed roll assembly to rotate about a horizontal axis 49 through thebolts 4l,'the slots 17 providing the necessary clearance. By this means,the feed roll 20 is enabled to float on the wooden materials in thechute, assuming a higher elevation when more material is in the chuteand a lower elevation when less material is present or when the materialitself is of a smaller size.

The feed roll 20 is positioned a sufficient distance rearward of thedrum 26 such that it will be effective in directing wooden materials tothe cutting station, that is, the roll 20 is positioned close enough tothe drum 26 to prevent the wood from tipping up as it approaches thecutting bar 31.

The cutting teeth 50 which are attached to the periphery of the drum 26are another feature of the present invention. Referring to FIG. 6,theteeth 50 are made by cutting a one-inch square cross sectionmanganese steel bar 51 containing 1 l to 14 percent manganese with anabrasive cutoff blade into three-inch long segments 52. The segments 52are cut on parallel planes 53 at an acute angle B with the longitudinalaxis 54 of the bar 51. Angle B is preferably 50 Manganese not be drawninto a position whereby crushing and cutsteel of this constituency willimpact workharden to as high as 550 BI-IN.

A hard facing rod is then welded to the cutting tip 55 of each cuttingtooth 50 so formed and the hard facing material is then ground back toform a cutting edge having increased resistance to impact and abrasivewear. A hard facing electrode suitable for the purpose is that soldunder the trademark AMSCO X-S 3 which has a hardness ranging from 50 to54 Rockwell C.

The teeth 50 are then welded to the periphery of the drum 26 in a spiralwrap using a welding rod adapted to weld manganese steel to mild carbonsteel. A welding rod suitable for the purpose is disclosed in [1.5. Pat.No. 3,1 18,760 and is sold under the trademark AMSCO NICRO-MANG. In theattachment of the teeth 50 to the periphery of the drum 26, a greaterthickness of welding material is used at the forward edge 56 than at therear to achieve a relief. See FIG. 4. I have found that a one-quarterinch thickness of welding material at the front of each tooth givessufficient relief. The teeth SO-are attached to the periphery of thedrum 26 so that the forward cut surfaces 53 are undercut in thedirection of rotation o f the drum 26 to provide the cutting edges 55.Again see FIG. 4.

Placement of the teeth 50 on the periphery of the drum 26 is asillustrated in FIG. 5. For a drum having an axial length of 20 inches, Ihave found that 25 teeth disposed in two spiral wraps around theperiphery give sufficient overlap. Use of 25 teeth cut from a one-inchcross section bar on a 20 inch long drum results in five inches of suchoverlap in the two spiral wraps, and this has been found to besatisfactory.

Cutting the teeth on a 50 angle (angle B) increases the strength of theteeth and minimizes breakage. Making the teeth of manganese steel of thecomposition aforementioned results in an apparatus that can crush, shredand cut any type of wooden material and is immune to breakagenotwithstanding the presence of pieces of metal or rock embedded in thewood or included therewith. Manganese steel of the aforementionedconstituency also impact workhardens during use, thereby toughening theteeth during the life of the apparatus. If the teeth have to besharpened, such can be accomplished on the drum.

The geometric relationship between the drum 26 and cutting bar 31results in an apparatus which can function with the advantageouslylesser number of teeth herein disclosed. Using only two spiral wraps ofteeth around the periphery of the drum results in a maximum of aboutfour teeth being in any with the work at an time. Fewer teeth createcoarser pieces which are desirable in that such exhibit speedier decaycharacteristics. A lesser number of teeth also requires less feedingforce on the part of the roll 20 and effectively results in more cuttingpower per tooth. Fewer wraps of teeth around the periphery also make itpossible to cut bigger material; and the less teeth used on the drum,the less expensive it is to construct the apparatus.

Using teeth having the aforementioned characteristics and positioned asdisclosed on the drum results in the wooden materials being crushed,shredded and cut into different sized pieces which do not compact whendeposited on the ground and which decay faster than has been knownheretofore. The teeth break and crush the wood fibers and thisaccelerates biological breakdown. The geometric relationship between thedrum 26 and cutting bar 31 also results in the formation of many longstringy pices which help hold a mass of cut pieces together. This isespecially desirable if, for example, the pieces are spread on ahillside. Finally, the absence of carbide inserts as are often used incutting teeth avoids the recurrent breakage to which such teeth aresubject.

FIG. 7 and 7A illustrate an alternate form of tooth suitable for usewith the invention. In this construction, the teeth 60 are cut from thebar 51 along parallel planes 61 which are perpendicular to neither pairof opposed surfaces of the bar. This is in contradistinction to theteeth illustrated in FIGS. 4 and 6 wherein the cutting planes 53 areperpendicular to one pair59 of opposed surfaces of the bar 51, whichpair 59 are disposed perpendicular to the axis 27 of the drum 26 asillustrated. The teeth illustrated in FIG. 7 and 7A perforce strike thematerial with a cutting point 62 instead of a cutting edge, and thisachieves a self-cleaning function.

FIGS. 8 and 8A illustrate another form of tooth 70 suitable for use withthe present invention. This tooth has a cutting edge 71 perpendicular tothe longitudinal axis 54 of the bar, but is otherwise formed with a skewundercut which increases transversely from one side 72 to the other side73 as illustrated.

I claim:

1. Apparatus for cutting and shredding wood, comprising chute means forreceiving wooden materials and delivering the same to a cutting station,

a cutting bar mounted on one end of said chute means and having acutting edge on which said material is adapted to be cut; 2

a cutting drum adjacent said one end of said chute means, said drumbeing mounted for rotation about an axis transverse to the longitudinalaxis of said chute means,

a radial plane of said cutting drum which includes said cutting edge ofsaid cutting bar forming an acute angle with said floor of said chutemeans whereby the periphery of said drum depends below said floor ofsaid chute means,

said angle being sufficiently large to facilitate selffeeding of saidmaterial through the space defined by said periphery of said drum andsaid cutting edge of said cutting bar,

said angle being ofa magnitude less than the value at which saidmaterials would be drawn under said drum to jam the same;

plurality of hard metal teeth spirally attached to said periphery ofsaid cutting drum for crushing said wooden materials and cutting thesame on said cutting bar,

said teeth comprising segments of a rectangular bar cut on parallelplanes at each end thereof, said planes forming an acute angle with thelongitudi- 5 nal axis of said bar,

one of the uncut surfaces of said bar being positioned generallytangential to said periphery of said drum,

the forward surfaces of said teeth being undercut 10 in the direction ofrotation of said dr 1 n 1 w means toihvs''idfifierii aTohEsEidiToor ofsaid chute means to said cutting station; and power means for rotatingsaid drum. 2. Apparatus as in claim 1 in which said angle between saidradial plane of said cutting drum and said floor of said chute means isabout 45.

3. Apparatus for crushing and cutting wooden materials comprising a drummounted for rotation about a horizontal axis;

a plurality of hard metal teeth attached to the periphery of said drum,said teeth comprising segments of a rectangular bar cut on parallelplanes at each end thereof, said planes forming an acute angle with thelongitudinal axis of said bar, one of the uncut surfaces of said barbeing positioned generally tangential to said periphery of said drum,the forward surfaces of said teeth being undercut in the direction ofrotation of said drum; cutting means positioned adjacent said drum andon which said materials can be cut by said teeth; means to feed saidmaterials to a position adjacent said drum and said cutting means; and

means to rotate said drum to cause said teeth to cut said materials onsaid cutting means.

4. Apparatus as in claim 3 in which said teeth comprise manganese steelteeth.

5. Apparatus as in claim 3 in which said parallel planes are parallel tosaid axis of said drum.

6. Apparatus as in claim 3 in which said rectangular bar comprises a barof square cross section.

7. Apparatus as in claim 6 in which said teeth are disposed in only twospiral wraps around said periphery of said drum.

8. Apparatus as in claim 3 in which said acute angle between saidparallel planes on which said rectangular bar is cut and saidlongitudinal axis of said bar is about 50.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. ,8 1,27 Dat d April 2 1974 Inventor(s) WAYNE H. KUBITZ It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 66, "vew" should be --view--;

Column 3, line 28, "t" should be --at--; Q

line 68, after "50" insert -degrees--; Column 4, line 50, "any" shouldbe --contact and "an" should be --any--.

Signed and sealed this 9th day of July 1974.

Attest: I I

McCOY M. GIBSON, JR. C. MARSHALL DANIN Attesting Officer Commissioner ofPatents YORM PO-1050 (IO-69) USCOMM-DC scan-ps9 I i- U.S. GOVERNMENTPRINTING OFFICE: I969 0-366-334

1. Apparatus for cutting and shredding wood, comprising chute means forreceiving wooden materials and dElivering the same to a cutting station;a cutting bar mounted on one end of said chute means and having acutting edge on which said material is adapted to be cut; a cutting drumadjacent said one end of said chute means, said drum being mounted forrotation about an axis transverse to the longitudinal axis of said chutemeans, a radial plane of said cutting drum which includes said cuttingedge of said cutting bar forming an acute angle with said floor of saidchute means whereby the periphery of said drum depends below said floorof said chute means, said angle being sufficiently large to facilitateself-feeding of said material through the space defined by saidperiphery of said drum and said cutting edge of said cutting bar, saidangle being of a magnitude less than the value at which said materialswould be drawn under said drum to jam the same; a plurality of hardmetal teeth spirally attached to said periphery of said cutting drum forcrushing said wooden materials and cutting the same on said cutting bar,said teeth comprising segments of a rectangular bar cut on parallelplanes at each end thereof, said planes forming an acute angle with thelongitudinal axis of said bar, one of the uncut surfaces of said barbeing positioned generally tangential to said periphery of said drum,the foward surfaces of said teeth being undercut in the direction ofrotation of said drum; means to move said material along said floor ofsaid chute means to said cutting station; and power means for rotatingsaid drum.
 2. Apparatus as in claim 1 in which said angle between saidradial plane of said cutting drum and said floor of said chute means isabout 45*.
 3. Apparatus for crushing and cutting wooden materialscomprising a drum mounted for rotation about a horizontal axis; aplurality of hard metal teeth attached to the periphery of said drum,said teeth comprising segments of a rectangular bar cut on parallelplanes at each end thereof, said planes forming an acute angle with thelongitudinal axis of said bar, one of the uncut surfaces of said barbeing positioned generally tangential to said periphery of said drum,the forward surfaces of said teeth being undercut in the direction ofrotation of said drum; cutting means positioned adjacent said drum andon which said materials can be cut by said teeth; means to feed saidmaterials to a position adjacent said drum and said cutting means; andmeans to rotate said drum to cause said teeth to cut said materials onsaid cutting means.
 4. Apparatus as in claim 3 in which said teethcomprise manganese steel teeth.
 5. Apparatus as in claim 3 in which saidparallel planes are parallel to said axis of said drum.
 6. Apparatus asin claim 3 in which said rectangular bar comprises a bar of square crosssection.
 7. Apparatus as in claim 6 in which said teeth are disposed inonly two spiral wraps around said periphery of said drum.
 8. Apparatusas in claim 3 in which said acute angle between said parallel planes onwhich said rectangular bar is cut and said longitudinal axis of said baris about 50*.